When you have the Snap&Read toolbar open in the Safari browser you can long touch on tools icon (Speaker tool , Text Leveling tool, or Translate tool) to change the settings.
Options/Settings you can change by long touching the Speaker tool:
Highlight Text Color
Highlight Background color
Highlight Paragraph color
Volume, Speed and Pitch of the voice selected.
Options/settings you can change when you long touch the Text Level tool:
Complexity of the Text Leveling.
Options/Settings you can change by long touching the Translate tool:
The language to translate into.
The translate voice.*
* Voices are not available for every languge